Stents are being used as a clinical device to maintain an effective internal scaffold within vascular structures. However, the ultimate utility of stent implantation maybe limited by adverse early and late biological responses. Both subacute thrombotic closure after stent placement and neointimal proliferation have resulted in untoward clinical results in some patients. In an effort to improve versatility and function of stents molecular biology techniques are being considered to reduce surface thrombogenicity and evoke more favorable biological responses. Since animal studies have indicated that rapid stent endothelialization markedly reduces early thrombus formation, this study was undertaken to seed metallic stents with genetically engineered endothelial cells incorporating the gene for either bacterial B-galactosidase or human tissue plasminogen activator. This work, supervised and performed in close collaboration with the Molecular Hematology Branch, indicated that seeding stents with genetically engineered endothelial cells was indeed feasible. These preliminary findings suggest the possibility that modification of the stent surface with partial or complete endothelial cell coverage might result in an environment less susceptible to thrombus formation with the potential for local delivery of pharmacologic substances which might ultimately improve stent function.